In serial communication systems, a large percentage of the total power is consumed in the transmitter, which must provide for adequate signal swing on a low-impedance channel while maintaining an appropriate source termination. In addition, the transmitter often includes equalization to compensate for frequency-dependent loss in the channel. The driver circuit in the transmitter often consumes the majority of the power of the transmitter. Driver circuits can be implemented as current-mode drivers or voltage-mode drivers. Voltage-mode drivers are known to consume far less power in comparison to current-mode drivers. For example, a voltage-mode driver can consume four times less DC power than a current-mode driver to provide the same output swing.
A transmitter can include a plurality of voltage-mode drivers coupled to a common output node. A voltage regulator provides a regulated supply voltage to the voltage-mode drivers. The voltage-mode drivers are driven by different input signals to implement equalization. Thus, the voltage-mode drivers draw a data-dependent current from the voltage regulator. Large swings in the average supply current can degrade the deterministic jitter of the transmitter.